It is questionable as to the real need to replace the gaskets but if you do you will need two lower cylinder gaskets, two lower head gaskets, two upper head gaskets, two valve cover gaskets, three yes three exhaust donut gaskets, two intake throttle body gaskets, and 4 new oil washer seals(for the L/H oil lines to the heads). In all about $200. The dealer screwed up and didn't order all I needed. I did not replace any of the gaskets because I am going to need to take it back apart for the cam and springs. Leaks pretty good but no big deal because it won't be long before I get the cam and it is winter now.So it took us, me and my buddy, about 16 hours to tear down and put back together. Make sure you mark all the wiring and tubes on both ends as some will plug in to different plugs. There are two bolts in the back of the back cylinder that are about impossible to get to. I drilled 1/4 inch holes thru the frame to get to these easily. You will want to do this only if you are confident with your drilling skills and aim. The frame is very thick there and if you do not aim well the holes will do you no good. When removing the aft cylinder valve cover, it needs to come out on the R/H side of the frame straight out. It is a very tight fit but will come out. Remember this for reinstallation. We did not and fought it for a long time and I was very frustraigted. Be very careful not to pry parts apart at the seal surfaces (use the fins) because the gaskets will not seal up marked up surfaces. Tear down the front cylinder first because you will need the room to get the aft one apart. You can do this with the motor in the frame. Make sure to mark the position of the push rods before removing the head. They twist as they go down so you need to mark them as FFO (forward cylinder, front rod outside at bottom) FBI (forward cylinder, back rod, inside at bottom). This way you know how to put them back in. I marked them and put them in wrong anyways. The forward cylinder would not fire when we put it together and we had to tear it back apart so check it twice.Everything comes apart quite easily really. Once the cylinders are off you will have to remove the piston pin retainers. Before you do this cover up the opening on the case at the lower end so nothing falls into the case IE your piston pin retainers. This would be a very bad thing. When you put in the new pistons there are no orientation markings but they are directional. The recesses in the top of the pistons for the valves are bigger diameter and deeper for the intake valves and these get oriented to the inside (intake valves to the inside and exhaust valves to the front and back). The new piston pin retainers are difficult to install. Make sure to Oil the pins. I used a pair of needle nose pliers and a flat screw driver. We did not figure out the orientation right away and had to remove and reinstall the aft one so check it twice. When you install the rings make sure to measure the gaps of all of them inside one of the cylinders. I did not have to do anything to any of mine, they were all perfect as I would guess yours will be. You did get rings with the pistons right? Refer to the service manual for orientation but note that the pictures are not to angular scale. The upper and lower oil seal rings (the lower thin rings) sit 45* from centerline of the bike and 180* opposite each other and the upper two rings sit 90* to the oil rings and 180* opposite each other. It does not look like it in the manual. When you do the rings start with one of the thin ones and put it all the way down the piston past the spot it goes in and then put in the oil seal ring and then slide it up over the oil ring and then slide the other thin one over the top of the oil ring. Then install the (I think) the thicker ring and then last the thinner of the two thick rings. Note here that the new upper two rings are different thicknesses where the original rings are both the same thickness so make sure you pay attention to this.You do not need to compress the rings to get the cylinders back on which really surprised me. They thought ahead and tapered the bottom of the cylinders so one person can squeeze on the rings and wiggle them while the other person wiggles on the cylinder and it will slip right on. Slide it down all the way. Do both cylinders and then install the aft head and valve cover. Make sure to put the aft all together before installing the throttle body otherwise the valve cover will not go on. Set the throttle body in place loose to the aft cylinder head then install the front head and valve cover. Remember to be very careful about the lifter orientation. Refer to the service manual for all torques and sequence of torques on the head, very important.This is a very important step. Jack up the back. Take a plug out of the front and back cylinder and put the bike in second gear and rotate the back tire thru a couple of engine revolutions to make sure there are no clearance issues inside the motor. This verifies you will not tear up anything when you attempt to start is. (errors in reassembly).Back on the ground, finish reinstalling all loose items and start it up. Good luck. My lack of attention on the front cylinder push rods cast me a lot of frustration.
If you think about, make sure the gas tank is near empty because you will want to fill up with Premium. No more running regular. And have a half quart of oil. You are going to loose that much. You could drain it but not really required. It is not that messy.
Let me know if you have any questions